The present invention relates to an optical system for recording or projecting a panoramic image. In particular, the system can be used with a movie projector to project a 360.degree. panoramic image or the system can be used with a camera such as a VCR, a professional movie camera or even a camera for taking still pictures.
U.S. Pat. No. 3,822,936 discloses an optical system for panoramic projection which is capable of producing a 360.degree. image on a circular screen surrounding an audience. In particular, this patent discloses a system of frusto-conical, optically-reflective surfaces arranged in adjustable relationship to enable a projector located above and out of the area of the audience to display a panoramic view on a 360.degree. screen surrounding the audience. One embodiment disclosed in this patent includes a motion picture projector disposed above a ceiling and a circular projection screen with an interior reflective coating located in the space below the ceiling and positioned concentrically with respect to an aperture in the ceiling through which the images are projected. An optical prism is located in front of the projector and over the aperture, the prism having an interior optically reflective surface for reflecting the projected image in alignment with the central axis of the aperture. Three frusto-conical elements are provided for reflecting the projected image onto the circular screen. The first element is conical in shape and has an exterior optically reflective surface for reflecting the projected image from the prism onto a second one of the elements. The second element has an interior optically reflective surface for reflecting the projected image onto the third element. The third element has an exterior optically reflective surface for reflecting the projected image onto the circular screen.
U.S. Pat. No. 3,846,809 discloses a system of frusto-conical and hemispherical reflectors mounted on a supporting structure for attachment to the interior or exterior of a camera lens barrel to provide panoramic viewing. In particular, a reflector is slidably mounted on a slender transparent stem member which is fixed to and in perpendicular relationship to a transparent disk which is externally threaded to screw into the lens barrel of a camera. The reflector is of composite shape and includes two surfaces of revolution, a frusto-conical portion and a hemispherical portion. The surfaces of the reflector are so oriented that incoming light rays are reflected along the axis of the camera which is concentric with the axis of the surfaces of revolution. The stem does not interfere with the reflected light and a complete picture of the panorama is thereby formed on the camera film.
The prior art arrangement of U.S. Pat. No. 3,822,936 allows the projector to be hidden from view in a space above a ceiling but the projector is not portable whereas the camera used in the prior art arrangement of U.S. Pat. No. 3,846,809 cannot be hidden from view even though it is portable. Accordingly, there exists a need in the art for an optical system for recording or projecting a panoramic image which allows the camera or projector to be hidden from view and which allows the system to be portable or fixedly mounted when in use. Furthermore, there is a need in the art for a panoramic system which provides distortion free images.